Skew Schubert polynomials

We define skew Schubert polynomials to be normal form (polynomial) representatives of certain classes in the cohomology of a flag manifold. We show that this definition extends a recent construction of Schubert polynomials due to Bergeron and Sottile in terms of certain increasing labeled chains in Bruhat order of the symmetric group. These skew Schubert polynomials expand in the basis of Schubert polynomials with nonnegative integer coefficients that are precisely the structure constants of the cohomology of the complex flag variety with respect to its basis of Schubert classes. We rederive the construction of Bergeron and Sottile in a purely combinatorial way, relating it to the construction of Schubert polynomials in terms of rc-graphs.Comment: 10 pages, 7 figure

Two Decreasing Measures for Simply Typed ?-Terms

This paper defines two decreasing measures for terms of the simply typed ?-calculus, called the ?-measure and the ?^{?}-measure. A decreasing measure is a function that maps each typable ?-term to an element of a well-founded ordering, in such a way that contracting any ?-redex decreases the value of the function, entailing strong normalization. Both measures are defined constructively, relying on an auxiliary calculus, a non-erasing variant of the ?-calculus. In this system, dubbed the ?^{?}-calculus, each ?-step creates a "wrapper" containing a copy of the argument that cannot be erased and cannot interact with the context in any other way. Both measures rely crucially on the observation, known to Turing and Prawitz, that contracting a redex cannot create redexes of higher degree, where the degree of a redex is defined as the height of the type of its ?-abstraction. The ?-measure maps each ?-term to a natural number, and it is obtained by evaluating the term in the ?^{?}-calculus and counting the number of remaining wrappers. The ?^{?}-measure maps each ?-term to a structure of nested multisets, where the nesting depth is proportional to the maximum redex degree

Agregando polimorfismo a una lógica que identifica proposiciones isomorfas

Sistema I es un cálculo lambda simplemente tipado con pares, extendido con una teoría ecuacional obtenida a partir de considerar a los tipos isomorfos como iguales. En este trabajo presentamos una extensión de Sistema I a polimorfismo, agregando los isomorfismos correspondientes, y proveemos pruebas no estándar de las propiedades de preservación de tipos y normalización fuerte.Sociedad Argentina de Informática e Investigación Operativ

Agregando polimorfismo a una lógica que identifica proposiciones isomorfas

Tanto los sistemas de tipos como los sistemas de pruebas distinguen elementos que tienen diferente forma aunque tengan el mismo significado, como pueden ser las pruebas de las conjunciones AB y BA, por lo cual una prueba de una no constituye una prueba de la otra, a pesar de que se puede demostrar mediante la existencia de un isomorfismo que dichas proposiciones son equivalentes. Sistema I es un cálculo lambda simplemente tipado con pares, extendido con una teoría ecuacional obtenida a partir de los isomorfismos de tipos existentes entre los tipos simples con pares, de forma tal que las proposiciones con mismo significado son equivalentes. En este trabajo proponemos una extensión de Sistema I hacia polimorfismo, añadiendo al sistema de tipos el cuantificador universal y sus isomorfismos relacionados.Facultad de Informátic

An End-User Semantic Web Augmentation tool

Web Augmentation is usually applied to add, remove and change Web sites’ functionalities, content, and presentation. Content- based Web Augmentation is commonly performed by integrating con- tent from an external Web site into the current one. In this article, we explore the use of the Semantic Web as a source of information to be incorporated to any Web site, aiming to simplify the development of Web Augmentation based on Semantic Web data. Our approach allows end-users without any programming skills to build Web Augmentation scripts that takes some information from the current Web page, and produce new related information gathered from the Semantic Web. This article introduces a pipeline process for building SWA and an End-User Development tool called SWAX to create augmentation layers without the need for any programming or SW skills.Publicado en Lecture Notes in Computer Science book series (LNCS, vol. 11553).Laboratorio de Investigación y Formación en Informática Avanzad

An End-User Semantic Web Augmentation tool

Web Augmentation is usually applied to add, remove and change Web sites’ functionalities, content, and presentation. Content- based Web Augmentation is commonly performed by integrating con- tent from an external Web site into the current one. In this article, we explore the use of the Semantic Web as a source of information to be incorporated to any Web site, aiming to simplify the development of Web Augmentation based on Semantic Web data. Our approach allows end-users without any programming skills to build Web Augmentation scripts that takes some information from the current Web page, and produce new related information gathered from the Semantic Web. This article introduces a pipeline process for building SWA and an End-User Development tool called SWAX to create augmentation layers without the need for any programming or SW skills.Publicado en Lecture Notes in Computer Science book series (LNCS, vol. 11553).Laboratorio de Investigación y Formación en Informática Avanzad

An End-User Semantic Web Augmentation tool

Web Augmentation is usually applied to add, remove and change Web sites’ functionalities, content, and presentation. Content- based Web Augmentation is commonly performed by integrating con- tent from an external Web site into the current one. In this article, we explore the use of the Semantic Web as a source of information to be incorporated to any Web site, aiming to simplify the development of Web Augmentation based on Semantic Web data. Our approach allows end-users without any programming skills to build Web Augmentation scripts that takes some information from the current Web page, and produce new related information gathered from the Semantic Web. This article introduces a pipeline process for building SWA and an End-User Development tool called SWAX to create augmentation layers without the need for any programming or SW skills.Publicado en Lecture Notes in Computer Science book series (LNCS, vol. 11553).Laboratorio de Investigación y Formación en Informática Avanzad

Hacia un sistema I polimórfico

Sistema I es un lambda cálculo simplemente tipado con pares, extendido con una teoría ecuacional obtenida a partir de los isomorfismos de tipos existentes entre los tipos simples con pares. En este trabajo en progreso proponemos una extensión de Sistema I hacia tipos polimórficos, añadiendo al sistema de tipos tanto el cuantificador universal como sus isomorfismos relacionados.XVI Workshop Ingeniería de Software.Red de Universidades con Carreras en Informátic